Extract i18n strings from *.underscore files using django-babel-underscore

Change strings from mako.po into underscore.po, which is finally merged into djangojs.po.

conf/locale/babel_mako.cfg

@@ -11,9 +11,3 @@ input_encoding = utf-8
 input_encoding = utf-8
 [mako: lms/templates/emails/**.txt]
 input_encoding = utf-8
-
-[underscore: **.underscore]
-input_encoding = utf-8
-
-[extractors]
-underscore = django_babel_underscore:extract

conf/locale/babel_third_party.cfg

@@ -4,9 +4,3 @@ input_encoding = utf-8
 
 [django: **/template/**.html]
 input_encoding = utf-8
-
-[underscore: **.underscore]
-input_encoding = utf-8
-
-[extractors]
-underscore = django_babel_underscore:extract

conf/locale/babel_underscore.cfg

@@ -0,0 +1,6 @@
+# Use this configuration file for extracting strings from .underscore files.
+[underscore: **.underscore]
+input_encoding = utf-8
+
+[extractors]
+underscore = django_babel_underscore:extract

conf/locale/config.yaml

@@ -121,3 +121,4 @@ generate_merge:
     djangojs.po:
         - djangojs-partial.po
         - djangojs-studio.po
+        - underscore.po

i18n/extract.py

@@ -58,19 +58,27 @@ def main(verbosity=1):
     }
     babel_verbosity = verbosity_map.get(verbosity, "")
 
+    if verbosity:
+        stderr = None
+    else:
+        stderr = DEVNULL
+
     babel_mako_cmd = 'pybabel {verbosity} extract -F {config} -c "Translators:" . -o {output}'
     babel_mako_cmd = babel_mako_cmd.format(
         verbosity=babel_verbosity,
         config=base(LOCALE_DIR, 'babel_mako.cfg'),
         output=base(CONFIGURATION.source_messages_dir, 'mako.po'),
     )
-    if verbosity:
-        stderr = None
-    else:
-        stderr = DEVNULL
-
     execute(babel_mako_cmd, working_directory=BASE_DIR, stderr=stderr)
 
+    babel_underscore_cmd = 'pybabel {verbosity} extract -F {config} -c "Translators:" . -o {output}'
+    babel_underscore_cmd = babel_underscore_cmd.format(
+        verbosity=babel_verbosity,
+        config=base(LOCALE_DIR, 'babel_underscore.cfg'),
+        output=base(CONFIGURATION.source_messages_dir, 'underscore.po'),
+    )
+    execute(babel_underscore_cmd, working_directory=BASE_DIR, stderr=stderr)
+
     makemessages = "django-admin.py makemessages -l en -v{}".format(verbosity)
     ignores = " ".join('--ignore="{}/*"'.format(d) for d in CONFIGURATION.ignore_dirs)
     if ignores:
@@ -100,6 +108,8 @@ def main(verbosity=1):
 
     files_to_clean = set()
 
+    files_to_clean.add(source_msgs_dir / "underscore.po")
+
     # Extract strings from third-party applications.
     for app_name in CONFIGURATION.third_party:
         # Import the app to find out where it is.  Then use pybabel to extract